.\" Copyright (c) 2011 Kai Wang
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\" $Id: dwarf_def_macro.3 3644 2018-10-15 19:55:01Z jkoshy $
.\"
.Dd November 9, 2011
.Dt DWARF_DEF_MACRO 3
.Os
.Sh NAME
.Nm dwarf_def_macro
.Nd add a macro definition to a DWARF producer instance
.Sh LIBRARY
.Lb libdwarf
.Sh SYNOPSIS
.In libdwarf.h
.Ft "int"
.Fo dwarf_def_macro
.Fa "Dwarf_P_Debug dbg"
.Fa "Dwarf_Unsigned lineno"
.Fa "char *name"
.Fa "char *value"
.Fa "Dwarf_Error *err"
.Fc
.Sh DESCRIPTION
Function
.Fn dwarf_def_macro
adds a macro definition to a DWARF producer instance.
.Pp
Argument
.Ar dbg
should reference a DWARF producer instance allocated using
.Xr dwarf_producer_init 3
or
.Xr dwarf_producer_init_b 3 .
.Pp
Argument
.Ar lineno
specifies the line number of the source line where the macro is
defined.
A line number of zero is used for macros that are defined
before any source file is read.
.Pp
Argument
.Ar name
should point to a NUL-terminated string containing the name
of the macro.
For function-like macros this parameter should also include
parentheses and parameter names if any.
.Pp
Argument
.Ar value
should point to a NUL-terminated string containing the value
of the macro.
If the macro does not have a value, argument
.Ar value
should be set to NULL.
.Pp
If argument
.Ar err
is not NULL, it will be used to store error information in case of an
error.
.Sh RETURN VALUES
On success, function
.Fn dwarf_def_macro
returns
.Dv DW_DLV_OK .
In case of an error, function
.Fn dwarf_def_macro
returns
.Dv DW_DLV_ERROR
and sets the argument
.Ar err .
.Sh EXAMPLES
To record the fact that a macro named
.Dv _STDIO_H_
was defined at line 20 of the current macro file, use:
.Bd -literal -offset indent
Dwarf_P_Debug dbg;
Dwarf_Error de;

/* ... Assume 'dbg' refers to a DWARF producer instance... */
if (dwarf_def_macro(dbg, 20, "_STDIO_H_", NULL, &de) != DW_DLV_OK)
	errx(EXIT_FAILURE, "dwarf_def_macro failed: %s",
	    dwarf_errmsg(-1));
.Ed
.Sh ERRORS
Function
.Fn dwarf_def_macro
can fail with:
.Bl -tag -width ".Bq Er DW_DLE_ARGUMENT"
.It Bq Er DW_DLE_ARGUMENT
Either arguments
.Ar dbg
or
.Ar name
was NULL.
.It Bq Er DW_DLE_MEMORY
An out of memory condition was encountered during the execution of the
function.
.El
.Sh SEE ALSO
.Xr dwarf 3 ,
.Xr dwarf_end_macro_file 3 ,
.Xr dwarf_producer_init 3 ,
.Xr dwarf_producer_init_b 3 ,
.Xr dwarf_start_macro_file 3 ,
.Xr dwarf_undef_macro 3 ,
.Xr dwarf_vendor_ext 3
